These XMLs live in a separate directory, there's no need for them
to have a special prefix in addition. It also doesn't play nicely
with ':e' completion in Vim, finding proper file based on
qemuxml2argvtest.c is also needlessly complicated.

The files were renamed using the following commands. From
qemuxml2argvdata:

  for i in qemuxml2argv-*.xml; do mv $i ${i#qemuxml2argv-}; done

and then (to fix broken symlinks) from qemuxml2argvdata and
qemuxml2xmloutdata:

  for i in $(find . -xtype l); do \
      ln -sf $(readlink $i | sed 's/qemuxml2argv-//') $i;
  done
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Our test data used a lot of different qemu binary paths and some
of them were based on downstream systems.

Note that there is one file where I had to add "accel=kvm" because
the qemuargv2xml code parses "/usr/bin/kvm" as virt type="kvm".
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

Up until a while ago, libvirt would automatically add a legacy
PCI controllers combo (dmi-to-pci-bridge + pci-bridge) to any
PCIe machine type (x86_64/q35 and aarch64/virt).

As a result, a number of input and output files in the test
suite ended up containing the legacy PCI controllers, even
though they are not needed or in any way relevant to the
feature being tested.

Get rid of most of the occurrences. Most of the time, this
just means removing the controllers from the input file and
regenerating the output files; in a few instances, some
minor tweaking is performed on the input file, most notably
removing the memory balloon: as memory balloon support was
not the scope of the test being changed, there is no loss
of test coverage from doing so.

Several occurrences of the legacy PCI controllers remain in
the test suite, both because removing their usage would have
required even more tweaking, and because we still want to
have coverage of this perfectly valid combination.

libvirt may automatically add a pci-root or pcie-root controller to a
domain, depending on the arch/machinetype, and it hopefully always
makes the right decision about which to add (since in all cases these
controllers are an implicit part of the virtual machine).

But it's always possible that someone will create a config that
explicitly supplies the wrong type of PCI controller for the selected
machinetype. In the past that would lead to an error later when
libvirt was trying to assign addresses to other devices, for example:

  XML error: PCI bus is not compatible with the device at
  0000:00:02.0. Device requires a PCI Express slot, which is not
  provided by bus 0000:00

(that's the error message that appears if you replace the pcie-root
controller in a Q35 domain with a pci-root controller).

This patch adds a check at the same place that the implicit
controllers are added (to ensure that the same logic is used to check
which type of pci root is correct). If a pci controller with index='0'
is already present, we verify that it is of the model that we would
have otherwise added automatically; if not, an error is logged:

  The PCI controller with index='0' must be " model='pcie-root' for
  this machine type, " but model='pci-root' was found instead.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1004602

This patch adds in special handling for a few devices that need to be
treated differently for q35 domains:

usb - there is no implicit/default usb controller for the q35
machinetype. This is done because normally the default usb controller
is added to a domain by just adding "-usb" to the qemu commandline,
and it's assumed that this will add a single piix3 usb1 controller at
slot 1 function 2. That's not what happens when the machinetype is
q35, though. Instead, adding -usb to the commandline adds 3 usb
(version 2) controllers to the domain at slot 0x1D.{1,2,7}. Rather
than having

  <controller type='usb' index='0'/>

translate into 3 separate devices on the PCI bus, it's cleaner to not
automatically add a default usb device; one can always be added
explicitly if desired. Or we may decide that on q35 machines, 3 usb
controllers will be automatically added when none is given. But for
this initial commit, at least we aren't locking ourselves into
something we later won't want.

video - qemu always initializes the primary video device immediately
after any integrated devices for the machinetype. Unless instructed
otherwise (by using "-device vga..." instead of "-vga" which libvirt
uses in many cases to work around deficiencies and bugs in various
qemu versions) qemu will always pick the first unused slot. In the
case of the "pc" machinetype and its derivatives, this is always slot
2, but on q35 machinetypes, the first free slot is slot 1 (since the
q35's integrated peripheral devices are placed in other slots,
e.g. slot 0x1f). In order to make the PCI address of the video device
predictable, that slot (1 or 2, depending on machinetype) is reserved
even when no video device has been specified.

sata - a q35 machine always has a sata controller implicitly added at
slot 0x1F, function 2. There is no way to avoid this controller, so we
always add it. Note that the xml2xml tests for the pcie-root and q35
cases were changed to use DO_TEST_DIFFERENT() so that we can check for
the sata controller being automatically added. This is especially
important because we can't check for it in the xml2argv output (it has
no effect on that output since it's an implicit device).

ide - q35 has no ide controllers.

isa and smbus controllers - these two are always present in a q35 (at
slot 0x1F functions 0 and 3) but we have no way of modelling them in
our config. We do need to reserve those functions so that the user
doesn't attempt to put anything else there though. (note that the "pc"
machine type also has an ISA controller, which we also ignore).

This PCI controller, named "dmi-to-pci-bridge" in the libvirt config,
and implemented with qemu's "i82801b11-bridge" device, connects to a
PCI Express slot (e.g. one of the slots provided by the pcie-root
controller, aka "pcie.0" on the qemu commandline), and provides 31
*non-hot-pluggable* PCI (*not* PCIe) slots, numbered 1-31.

Any time a machine is defined which has a pcie-root controller
(i.e. any q35-based machinetype), libvirt will automatically add a
dmi-to-pci-bridge controller if one doesn't exist, and also add a
pci-bridge controller. The reasoning here is that any useful domain
will have either an immediate (startup time) or eventual (subsequent
hot-plug) need for a standard PCI slot; since the pcie-root controller
only provides PCIe slots, we need to connect a dmi-to-pci-bridge
controller to it in order to get a non-hot-plug PCI slot that we can
then use to connect a pci-bridge - the slots provided by the
pci-bridge will be both standard PCI and hot-pluggable.

Since pci-bridge devices themselves can not be hot-plugged into a
running system (although you can hot-plug other devices into a
pci-bridge's slots), any new pci-bridge controller that is added can
(and will) be plugged into the dmi-to-pci-bridge as long as it has
empty slots available.

This patch is also changing the qemuxml2xml-pcie test from a "DO_TEST"
to a "DO_DIFFERENT_TEST". This is so that the "before" xml can omit
the automatically added dmi-to-pci-bridge and pci-bridge devices, and
the "after" xml can include it - this way we are testing if libvirt is
properly adding these devices.

This controller is implicit on q35 machinetypes. It provides 31 PCIe
(*not* PCI) slots as controller 0.

Currently there are no devices that can connect to pcie-root, and no
implicit pci controller on a q35 machine, so q35 is still
unusable. For a usable q35 system, we need to add a
"dmi-to-pci-bridge" pci controller, which can connect to pcie-root,
and provides standard pci slots that can be used to connect other
devices.